Apparatus for automatically switching from gas fuel to oil fuel in dual fuel internalcombustion engines



Sept.- 30, 1952 G. STEVEN r-:T AL

APPARATUS FOR AUTOMATICALLY SWITCHING FROM GAS FUEL TO OIL FUEL IN DUAL FUEL. INTERNAL-COMBUSTION ENGINES Filed Nov. '7, 1951 GEGRGE STEVEN ROY R. FRUEHAUF INI/Emol@- Patented Sept. 30, 1952 APPARATUS FOR AUTOMATICALLY SWITCHING FROM GAS FUEL TO OIL FUEL IN DUAL FUEL INTERNAL- COIWBUSTION ENGINES George Steven,y Kenmore, and Roy R. Fruehauf,

Orchard Park, N. Y., assignors to Worthington Corporation, a corporation of Delaware Application Nvember 7, 1951, serial No. 255,198

Claims. (Cl. 12S-27) This invention relates to linternal combustion engines operating` on a mixture of fuel gas and air, fuel oil and air or a combination of both, either supercharged or naturally aspirated,` compression ignition or spark ignition, and more particularly to the control A of the supply of fuel, either gas `or fuel oil to the engine.

, More particularly the invention relates to an apparatus for rapidly changing from gas fuel with pilot oil operationl to operation of the engineV .on 100% oil fuel in response to a gas fuel failure.

Previous arrangements for such fuel changeover have involved the necessity ofl splitting the governor control linkage travel ,into two equal parts, utilizing one-halffor gas fuel operation and the other half for operation on oil fuel after the gas failure. v

Such arrangements involved acharacteristic of governor operation with respect to speed droop which is undesirable. With a governor speed droop setting for normal operation of any xed percentage, upon a failure of gas fuel when operation on the other half of the governor travel developed, the speed droop percentage would be approximately doubled. Such a condition upsets the distribution of load between engines which are operating in parallel with each other and may result in overloads or electrical discrepancies which -will create an engine shutdown.

Failure of gas fuel manifests itself by a rapid reduction in thepressure of gas supplied or in the pressure of theincoming gas tothe engine and the present invention embodies means utilizing such minimum gas pressure for actuating a device to rapidly change the engine over to 100 operation `by fuel oil and at the same time permit utilization of the fuel governor travel for either gas fuel or oil fuel under any circumstances and eliminates the undesirable characteristie of speed droop change and cyclic disturbance which can also effect the load condition on the electrical apparatus, which due to automatic devices incorporated for protective reasons ma shut down the engine.

With'these and other objects in view, as may appear from the accompanying specification, the invention consists of various features of construction and combination of parts, which ywill be first described in connection with the accompanying drawings, vshowing apparatus for automatically switching from gas fuel to oil fuel in a dual fuel internalcombustion engine of a` preferred form embodying the invention,A and the features forming the invention will be specifically pointed'outinthe claims.l L

In the drawings: f Figure 1 is a diagrammatic View partly in sec tion and partly in elevation of a fragment of an internal combustion engine equipped with the automatic fuel changeover mechanism of vthe present invention.

Figure 2 is a detail section through a valve structure employed in the automatic fuel changeover mechanism.

Figure i of the drawings shows a fragmentary section of a naturally aspirated dual fuel engine, capable of operation on a mixture of air vand gas, air and fuel oil, or on a combinationof gas, fuel oil and air. The engine includes the usual cylinder I in which a piston 2 reciprocates. The cylinder I has an air and gas fuel inlet port 3 controlled by an intake valvev 4 and which port communicates with the air intake passage 5. The exhaust port 6 which is controlled by an exhaust valve 'I communicates with the exhaust passage 8. Gas fuel is delivered into the intake 5 through the gas metering valve 9 and passage Ill under control of the valve II vwhile-fuel oil, both for the lpilot ignition chargeand for power charge is delivered to the cylinder I through the fuel injection or spray valve I2. l

Fuel and pilot injection fueloil is delivered to the injection or spray valve I2 by theffuel pump I3. .1

The operationof the fuel rpumpA I3 andthe gas metering valve 9 are-under control of the erigine governor I4 through the manual1yjset, con trolled cam I5. The cam I5 is slidably supported for longitudinal movement and has anl operating knob 36 thereon, although a lever may -be connected to the cam for operating it if desired. A cam roller I6 engages the camY I 5 and is carried by the fuel pump lever link Il which is connected by a series of links I8 and a bell crank I9 tothe fuel Vpump operating shaft 20. -The fuel puinp lever or link II is connected by a rod or a gevernor fuel pump link 2| to the governor rocker lever 22. The governor rocker lever 22 is con-gv nected by the link 23 to the governorlever 2i which is connected to and operated by the governor I4. y n

A second cam roller 2 5 engages the cam bar I5 and is carried by the control valve cam link 26.7 'l'he end of the link 26 remote from the roller 25 1s pivotally connected to a pivoted controlvalve cam lever 2l and to a link 28. ,The link 28 isA con-,1 nected to the end of the governor rocker` lever 22 remote from the connection of the link 2| tothe rocker lever. Links 29 and 30 connectthe'control valve cam link 21 to the pivoted lever 3| which is connected to the stem of the gas metering. 'valve' 9 and operates or moves the gas metering valve in response to action of the governor I4.

When the cam I is moved into the position indicated by the dotted position 36a o-f the knob 36 the roller I6 assumes the position Ia and the roller 25 assumes the lposition 25a still on the maximum land 32 of the cam I5, at which time the mechanism is set for the engine to run on a fuel mixture of fuel oil and air, or as an oil or diesel engine and the gas metering valve 9 will be held closed. When the cam I5 is moved into the position indicated by the dotted line position 36h of the knob 3B the cam rollers I5 and '25 are moved into the dotted line positions Ib and 25h respectively, which places the gas metering valve 9 under control of the governor I4 as well as the fuel pump I3, and during such time as there is sullcient gas fuel to operate the engine to meet its load requirement, only a pilot ignition charge of oil is delivered to the injection or spray valve rIZan'cl the engine operates as an oil ignited gas fuel engine, or as a gas diesel. However, when 'the supply of fuel gas is insuicient to meet the "load demands of the engine then the governor acts to augment the gas fuel supply by proportionate increase in the supply of lfuel oil. Intermal combustion engines of this type and operating on the same principle, vshowing slightly diere'nt control arrangements are shown in United States Patents No. 2,400,219 and No. 2,400,'247,issued May 14, 1946.

ZAs hereinabove set forth, reduction in the supplyof lgas to the engine manifests itself by 'a rapid reduction the pressure of the incoming gas and the present invention contemplates means operated by such a reduction in the Ipressure of the gas to completely cut oIT the supply of gasto the engine andl convert it to 100% operation on fuel oil, thus avoiding the undesirable characteristie of speed droop-change and cyclic disturbance 'above referred to which -occurs with the changeover of the engine above described.

the present invention the lever 40 is con- 'nected to the gas metering valve operating link or rod 30. The lever y4I] is pivotally supported intermediate its ends 'as shown at 4I and an adinstablev stop 42 'is provided for limiting the movement of the lever inone direction. The free 'end f the lever 4D rides in a slot 43 in a locking latch 44. The locking latch A44 is carried by the piston rod 45 which is in turn connected to a piston 45 mounted for reciprocation in a cylinder l41. The end of the locking latch 44 opposite to the'end connected to the piston rod 45 is engaged by the -end Aoi" a spring pressed rod 48 which "is enclosed in a suitable housing v49 and engaged by a spring 50.

The piston 46 is forced upwardly into the position shown in Figure 1 for moving the locking latch '44 against the tension of the spring 50 by pressure air which may be taken from any suitable source but which in Figure 1 of the drawings is shown as being taken from theair receiver 5I `which supplies the starting air for starting the engine. The air from the air receiver 5I passes through a pipe 52 in 'which is mounted a manually operated valve 53 to and through the pressure valve operated structure 54 and through a suitable flow control valve 55 into the bottom ofrth'e cylinder 41.

Y'The pressure actuated valve structure 54 includes a valve casing 56, Fig. 2, in which is reciprocably mounted a valve piston 51 having an vannular cutout 58 to provide communication between thepipe 52 on opposite sides of the valve 54 and it is provided with an elongated cutout 59 to establish pressure bleed-off connection between the outlet port 60 which leads to the cylinder 41 and the bleed-01T portV 6I sol thatl when the valve piston 51 is i-n its inward positicnthe pressure air will be bled from the cylinder 41. The stem 62 of the valve piston 51 has a knob Y63 thereon to facilitate initial manual setting of the valve piston 51.

IIhe valve piston 51 has a second stem 64 connected thereto which extends into the sealed housing 65 and is connected to a diaphragm 56. The diaphragm '65 is spring loaded by spring 51 so as to urge the valve piston 51 into position for bleeding air from the cylinder 41.

A branch pipe 68 communicates with the pipe 52 and leads to an automatic controller B9. The automatic controller 69 is a mechanism which measures the value of a variable quantity or condition and operates to vcorrect it to a selected value and such controllers are Well known and maybe purchased upon the open market. Such control'- 1ers are manufactured by The Bristol Company, Moore Products Co.vand others. The pressure air from the pipe 52 enters the automatic controller 68 through the pipe 58 and leaves the controller through a pipe 1U which is connected to .the interior of the sealed-casing 65 at .the side of `the diaphragm `56 opposite to the spring 61 so that the pressure of air acting on the diaphragm 56 will tend to force the valve piston 51 outwardly to open the pipe 52 through the vthree-way valve structure 54 to permit delivery of air-to the cylinder 41.

In the application of theV controller 59 in the present invention it'utilizes variances in the pressure of the incoming gas to the engine to control the delivery of air into the sealed .casing 65 of the pressure actuated three-way valve structure 54. A pipe 12 connects the automatic controller 69 to the gas supply receiver 13 which receives the gas from the gas compressor (not shown) and delivers it to the gas intake passage I0 on the upstream side ofthe gas meteringr valve 9.

Variances in the pressure of the incoming gas to the engine are transmitted to the automatic controller 69 and acts as a control pressure which regulates the delivery of the air from the pipe 52 against the diaphragm E6 for operating the piston 51 of the three-way valve 54 and'thus the delivery of air under pressure to the cylinder 41 is controlled in accordance with predetermined Variances 'in the pressure of the incoming eas. However, the controller 69 is set so that Vwhen the pressure of the incoming gas falls below 'a predetermined degree the supply of airy to v'the sealed housing 55 and adjacent the' diaphragm 66 will be cut off allowing the spring 61 to expand.

lmove the diaphragm and move the valve piston 51 inwardly to connect the interior of the cylinder 41 with the bleed-off port 6I, at which time the pressure air will be bled from the cylinder`41 and the spring 50 Will act to move the locking latch 44 downwardly and to` move the lever 40 into the position shown in solid lines in Figure 1 of the drawings. This movement of the lever 40 will. through the medium of the link 35 and lever 3|, -move the gas metering valve into complete closed position. The movement of 'thelocking latch 44 downward under action of 'the spring-50 will lock the lever 40 in its lowermost position as shown in solid lines in Figure 1 of the draw;

' y ings and prevent the lever 40 from 'any further I movement of the 'lever 40 into'its lowermost'. valve closing position locates the fulcrum point A of the lever 22immediately to its lowermost position permitting the governor lever 24 acting on, the lever 22 and pivotl C thereof to position the point B of the lever 2| to its upward position shown by' the dot and dash lines D to maintain the load carrying capacity operation of the engine `with 100% operation on fuel oil. It can be clearly seen, therefore, 'that' the governor lever 24 vwill always operate through its maximum permissible travel regardless oi what type of fuel the engine is being supplied with. `By venting the pressure air from the automatic controller 69' and the cylinder 41 to atmosphereit is impossible for the engine to revert to gas operation if thev gas supply for any reason reaches a suitable pressure for operation of the engine by gas fuel so long as 4the'valve *piston 51fremainsin its pressure fair bleeding'positionf 1 However, when or at such time as the vgas pressure vand gas supply is sufllcient to operate the engineundergas fuel the valve piston" 51 -is-manuallyjmoved outwardlyor the three-way valve 54 is manually set through the medium-of the knob-63 and stem B2 and this opens thepressure airsupply through the three-way valve 54 to both the cylinder 41 and the automatic controller 69.

The gas pressure to the automatic controller` 69 being sufficient to operate it to permit the passage'of pressureair therethrough, suchpressure air is delivered agalnst'the diaphragm' and holds the valve'piston 51 in its open. position. Theair under pressure entering the cylinder 41 willmove the lockinglatch-upwardly against the tension of the spring 50 and release the levei` 40 froml its locked position, thus permitting the lever 401' to move freely from the position'shown by. solid lines into the dot and dash vline position shown in Figure 1 of the drawings. 'Ihis travel of the lever 40 is the yfull amount of travel necessary to control the gas metering valve 9 from minimum to maximum positions and` to allow control of the supply of fuel gas to therengine .in accordance with load `demands under control of the governor I4. v y

It may be necessary to reduce the pressure of theair in the pipe or line 52 as it is delivered to the automatic controller 69 as well as to strain it, and therefore a lter or trap 80 and reducing valves 8l and 82 are interposed in the pipe 68. These elements 80, 8l and 82 are well known and may be purchased upon the open market. When the valve piston 51 is in position for bleeding the pressure air from the cylinder 41 it also bleeds the pressure air from the automatic controller 69 since the pipe 68 is connected to the pipe 52 on the downstream side of the pressure actuated three-way valve 54.

It will be understood that the invention is not to be limited to the specic construction or arrangementof parts shown, but that they may be widely modified within the invention defined by the claims.

What is claimed is:

1. The combination with a dual fuel internal combustion engine operable on a mixture of fuel gas and air, fuel oil and air, or a combination of both including a combustion chamber, a gas inlet passage, a gas metering valve controlling iiow of gas to said combustion chamber, a fuel oil inlet spray valve, a governor, and governor operated means for operating said gas metering valve and for controlling delivery of fuel oil to said spray valve, of governor operated means for i moving sala gas meteringvaives'meanssrrficeks ing; said governor operated. meansl to .holdz said gas metering valve in closed position; fandlmeans' `inlet passage, a gas? metering. valvefcontrolling 'flow of gas to said combustion chambeg=lafuel oil inlet vspray valve, aigovernor, andgoveror operated means for operating said gas metering valve and for controlling delivery :of l fuel ioil to said sprayrvalve, of governor operated means for lmoving said gas metering valve;rneansfor'lockev ing saidgovernor operated means Ii, o-'hold'said gas metering I valve in closed position, pressure operated meansforrele'asing said locking-means; and means controlled 'by pressure of entering `fuel gas forl controlling-f operation of 'said-@pressure operated means.

3. The combinauaonwith a dualV fueiinternai 'combustion engine operable onv a mixtureof fuel gas and air. fuel oil'and air. or a'combiflati'on .of both including a combustion chamber, la# gais inlet passage, a gas metering valvefc'ontrolling iiow of gasto said combustion chamber, a fuel voil inlet spray valve, a governor, and governor operated means for operating saidtgasmetering valve and yfor controlling delivery 'of'fuely voil-to saidi spray valve, of governor operatedmeang for moving said gas mteringvalve, meansgforidki ing saidv governor operated means-tohl'd said gas metering Vvalve in closedV position'prssu operated means'for releasingsaid'lock a' valve for 'controlling'L thel dlvj'r;L fluid to saidpressure operated`fmea""' controlled by pressure of ente-ifng-f-1"1l"3g.sl controlling operation `of said-valve? 4. The combination with a dual fuel-internal combustion engine operable on a mixture of fuel gas and air, fuel oill and air, or acombination of both including a combustion chambenla gas inlet passage, a gas metering valve 'controlling kflow of gas t0 saidcombustion -chamber`,-a"'fu`el oilin'let spray valve, a governor, and governor operated means for operating said gasmetering valve and.v for controlling delivery of fuel-oil t6 said spray valve, of governor operated means for moving said gas metering valve, means for locking said governor operated means to hold said gas metering valve in closed position, pressure operated means for releasing said locking means, la manually initially -set pressure operated valve for controlling delivery of pressure fluid to said pressure operated means, and means operated by pressure of entering fuel gas for controlling the operation of said pressure operated valve.

5. A dual fuel internal combustion engine as claimed in claim l wherein said locking means includes a locking latch, pressure operated means for moving said latch into unlocking position, and means for moving said latch into locking position upon release of pressure from said pressure operated latch moving means.

6.A A dual fuel internal combustion engine as claimed in claim 1 wherein said locking means includes a locking latch, pressure operated means for moving said latchv into unlocking position, and'means for moving said latch into locking position upon release of pressure from said pressure `operated latch moving means, and wherein saidv gas pressure controlled means includes means operated by pressure of incoming gas for sans 

